A Republican mayor from Indiana, James Brainard, who was attending the event, said he wants his party to take a firmer environmental stance.

"Our leadership is listening to too much of the pollution coming off talk radio and the TV shows," he said.

Last week, Brown and Senate leader Kevin de León (D-Los Angeles) dropped a proposal for reducing petroleum use by half over the next 15 years. The rest of the legislation, which increases renewable energy and energy efficiency, was passed by the Legislature, but lawmakers were not able to get enough support among Democrats for the gasoline component.